Hi ArleneKyte,
May I first give you a warm welcome to BPD Family ?

We are all here for mutual support on the same matter !

I would like to understand a bit more concerning the situation, may I ask you a few questions ?
Why did your mother finally agree to see a therapist ? Do you know if this therapist has any serious knowledge and most of all experience in helping people with BPD ? Do you know who the therapist is she's working with ?
Also, if she has BPD, keep something in mind : they are masters of manipulation (unknowingly) not to have to deal with guilt and shame themselves. What I mean is, that she just might be projecting the whole problem back to you, the family. It seems that the "truth" can evolve from moment to moment in another direction, making it them believe their own lies.
So it is hard to know and believe what the therapist actually said, you were not there. Have you been able to speak to her in the mean time ?
This may also be an interesting read for you :
Supporting a Loved-one with Borderline Personality DisorderHang in there, you are not alone !
Reg